Learning love lessons included grieving the loss of her relationship, and Katy bravely allowed cameras to capture an emotional backstage moment for her new concert film, "Katy Perry: Part of Me."

"What was going on in my personal life was so overwhelming that I had to bend over to let those tears fall straight out of my eye sockets and not my false lashes just as I'm about to go up on that ramp and sing 'Teenage Dream,'" she said. "I had to smack myself across the face and say, 'These problems are my problems, they are not my audience's problems, learn to separate that.'"

With hits like "Waking Up In Vegas" and "Last Friday Night (T.G.I.F.)," some may assume the 27-year-old singer like to spend her nights on the town. However, Katy said she prefers to spend her nights at home, rather than going out and getting "twisted," as she will "probably have to wake up and work in the morning" and now has "a lot more to lose."

For the full interview with Katy, pick up a copy of THR – on newsstands today.

Copyright 2012 by NBC Universal, Inc. All rights reserved.
This material may not be published, broadcast, rewritten or redistributed.